Sensor device scanning techniques to determine fast and/or slow motions

ABSTRACT

A method for performing navigation (NAV) operations using a sensor device comprising a plurality of transmitter electrodes includes: receiving, at an input sensing region of the sensor device, an input object; scanning, by the sensor device, the input object, wherein the scanning comprises driving a first subset of transmitter electrodes for low-resolution scanning and driving a second subset of transmitter electrodes for high-resolution scanning; and determining, by the sensor device, an input object motion based at least in part on the scanning.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of copending U.S. patentapplication Ser. No. 16/024,358, filed Jun. 29, 2018, which isincorporated herein by reference in its entirety.

BACKGROUND

Input devices, including touch sensor devices (also commonly calledtouchpads or proximity sensor devices), as well as fingerprint sensordevices, are widely used in a variety of electronic systems. Touchsensor devices typically include a sensing region, often demarked by asurface, in which the touch sensor device determines the presence,location and/or motion of one or more input objects, typically forpurposes of allowing a user to provide user input to interact with theelectronic system. Fingerprint sensor devices also typically include asensing region in which the fingerprint sensor device determinespresence, location, motion, and/or features of a fingerprint or partialfingerprint, typically for purposes relating to user authentication oridentification of a user.

Touch sensor devices and fingerprint sensor devices may thus be used toprovide interfaces for the electronic system. For example, touch sensordevices and fingerprint sensor devices are often used as input devicesfor larger computing systems (such as opaque touchpads, touch screensand fingerprint readers integrated in or peripheral to notebook ordesktop computers). Touch sensor devices and fingerprint sensor devicesare also often used in smaller computing systems (such as touch screensand fingerprint readers integrated in mobile devices such as smartphonesand tablets).

Touch sensor devices may be used for navigation (NAV) functions. NAVfunctions may include, for example, detection of the presence of afinger, as well as detecting gestures based on movement of a finger(such as tapping, double-tapping, scrolling, or swiping gestures). Itmay also be possible to use fingerprint sensor devices for NAVfunctions, but fingerprint sensor devices typically have a relativelysmall input sensing region (e.g., less than 10mm x 10mm), which makes itimpossible or impractical to detect fast-motion gestures such as fastswipe gestures through conventional imaging operations. Further,fingerprint sensor devices may have to contend with low signal-to-noiseratio (SNR) issues when disposed under a relatively thick substrate(such as a glass substrate of thickness 300 μm or greater).

SUMMARY

In an exemplary embodiment, the present disclosure provides a method forperforming navigation (NAV) operations using a sensor device comprisinga plurality of transmitter electrodes. The method includes: receiving,at an input sensing region of the sensor device, an input object;scanning, by the sensor device, the input object, wherein the scanningcomprises driving a first subset of transmitter electrodes forlow-resolution scanning and driving a second subset of transmitterelectrodes for high-resolution scanning; and determining, by the sensordevice, an input object motion based at least in part on the scanning.

In another exemplary embodiment, the present disclosure provides anon-transitory computer-readable medium having processor-executableinstructions stored thereon for performing navigation (NAV) operationsusing a sensor device. The processor-executable instructions, whenexecuted, facilitate performance of the following: scanning, by thesensor device, an input object at an input sensing region of the sensordevice, wherein the scanning comprises driving a first subset oftransmitter electrodes for low-resolution scanning and driving a secondsubset of transmitter electrodes for high-resolution scanning; anddetermining, by the sensor device, an input object motion based at leastin part on the scanning.

In yet another exemplary embodiment, the present disclosure provides amethod for performing navigation (NAV) operations using a fingerprintsensor device. The method includes: receiving, at an input sensingregion of the fingerprint sensor device, a finger; scanning, by thefingerprint sensor device, the fingerprint, wherein the scanningcomprises driving a first subset of transmitter electrodes of thefingerprint sensor device to determine finger coverage via one or morelow-resolution scans; and detecting, by the fingerprint sensor device,based on the scanning, a finger motion corresponding to a NAV operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram depicting an exemplary input device.

FIG. 2 is a block diagram depicting a further exemplary input device.

FIG. 3 depicts an exemplary orthogonal grid of transmitter electrodesand receiver electrodes of a fingerprint sensor device.

FIG. 4 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for a low-resolution scan.

FIG. 5A shows an example of a first scan being taken while a finger islocated on the left side of the exemplary orthogonal grid of transmitterelectrodes and receiver electrodes from FIG. 3.

FIG. 5B shows an example of a second scan being performed while a fingeris located over the entirety of the exemplary orthogonal grid oftransmitter electrodes and receiver electrodes from FIG. 3.

FIG. 5C shows an example of a third scan being taken while a finger islocated on the right side of the exemplary orthogonal grid oftransmitter electrodes and receiver electrodes from FIG. 3.

FIG. 6 is a flowchart depicting a process for using a fingerprint sensordevice to perform NAV operations corresponding to fast finger motions.

FIG. 7 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for a hybrid low-resolution/full-resolutionscan.

FIG. 8 is a flowchart depicting a process for using a fingerprint sensordevice to perform NAV operations corresponding to slow and/or fastfinger motions.

FIG. 9 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for an abbreviated hybridlow-resolution/full-resolution scan.

FIG. 10 is a flowchart depicting a process for using a fingerprintsensor device to perform NAV operations corresponding to slow and/orfast finger motions.

FIG. 11 is a flowchart depicting a process for using a fingerprintsensor device to perform NAV operations corresponding to slow and/orfast finger motions.

DETAILED DESCRIPTION

The following detailed description is exemplary in nature and is notintended to limit the disclosure or the application and uses of thedisclosure. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding background,summary and brief description of the drawings, or the following detaileddescription.

Fingerprint sensor devices may utilize transcapacitive sensingtechniques in connection with a plurality of transmitter (TX) andreceiver (RX) electrodes. Such fingerprint sensors may include an arrayof TX electrodes and receiver RX electrodes. The array may be configuredin various different ways, for example, in a bars-and-stripes pattern,in single-layer configurations with interdigitated electrodes, in matrixconfigurations where each pixel corresponds to an electrode plate, inorthogonal diamond configurations, etc. When a finger is placed onto thefingerprint sensor device, the TX electrodes are driven, and the RXelectrodes are configured to detect different capacitance valuescorresponding to ridges and valleys of the fingerprint, therebyproviding an image of the fingerprint (or part of the fingerprint)corresponding to the finger.

Since the signal level detected at the RX electrodes may be low, forexample when the fingerprint sensor device is disposed under a thickglass substrate upon which the finger is placed, techniques may be usedto enhance the signal level. For example, code division multiplexing(CDM) may be used with respect to transmitter signals driven onto the TXelectrodes. The CDM order, corresponding to the amount of TX electrodesbeing simultaneously driven, may be equivalent to the total number of TXelectrodes such that all TX electrodes are simultaneously driven for aplurality of sub-steps of a scan. Thus, a higher signal level isprovided by CDM since multiple TX electrodes can be driven at a time,relative to a non-CDM driving scheme where a single TX electrode isdriven at a time.

Transcapacitive fingerprint sensor devices may conventionally be usedfor NAV operations corresponding to relatively slow finger motions. Forexample, a slow finger gesture corresponding to a slow scroll operation(e.g., where a user may be trying to slowly scroll up or down a webpageor a document on a screen, or where a user may be trying to slowly movea cursor or pointer or a view on a screen) may move as slowly as, forexample, a few millimeters per second. These types of slow motions maybe detected by fully imaging the input sensing region multiple times,and detecting the slow scroll operation based on the movement offeatures of the fingerprint that can be seen across multiple capturedimages.

However, transcapacitive fingerprint sensor devices are notconventionally used for NAV operations corresponding to relatively fastfinger motions. For example, a fast finger gesture corresponding to aswipe operation (e.g., where a user may be trying to quickly scroll upor down a webpage or a document on a screen, where a user may be tryingto swipe left or swipe right to get to a previous or next page on ascreen, where a user may be trying to use a pull-down menu, or where auser may be trying to flip between images in a photo album), may move asquickly as, for example, 50 centimeters per second. These types of fastmotions cannot be reliably detected by fully imaging the input sensingregion, as the fast motion may cause the features of the fingerprint(e.g., ridge/valley information) to become blurred, or the fast motionmay be completed before multiple images of the input sensing region canbe captured.

Exemplary systems and methods discussed herein provide scanningtechniques for fingerprint sensor devices enabling NAV operationscorresponding to relatively fast finger motions, such as detecting afast swipe NAV operations. Exemplary systems and methods discussedherein further provide for hybrid scanning techniques such that afingerprint sensor device may be operated in a manner thatsimultaneously looks for slow and fast finger motions. These exemplarysystems and methods provide various advantages, for example, withrespect to improving frame rate, reducing computation complexity andpower consumption, improving NAV accuracy, and providing a solution thatsimultaneously looks for slow and fast finger motions.

FIG. 1 is a block diagram depicting an example input device 100 withinwhich the present embodiments may be implemented. The input device 100may be configured to provide input to an electronic system (not shownfor simplicity). As used in this document, the term “electronic system”(or “electronic device”) broadly refers to any system capable ofelectronically processing information. Examples of electronic systemsinclude personal computing devices (e.g., desktop computers, laptopcomputers, netbook computers, tablets, web browsers, e-book readers, andpersonal digital assistants (PDAs)), wearable computers (e.g., smartwatches and activity tracker devices), composite input devices (e.g.,physical keyboards, joysticks, and key switches), data input devices(e.g., remote controls and mice), data output devices (e.g., displayscreens and printers), remote terminals, kiosks, video game machines(e.g., video game consoles, portable gaming devices, and the like),communication devices (e.g., cellular phones, such as smart phones), andmedia devices (e.g., recorders, editors, and players such astelevisions, set-top boxes, music players, digital photo frames, anddigital cameras). Additionally, the electronic system may be a host or aslave to the input device 100.

The input device 100 may be implemented as a physical part of theelectronic system, or may be physically separate from the electronicsystem. The input device 100 may be coupled to (and communicate with)components of the electronic system using wired or wirelessinterconnections and communication technologies, such as buses andnetworks. Example technologies may include Inter-Integrated Circuit(I2C), Serial Peripheral Interface (SPI), Personal System/2 (PS/2),Universal Serial Bus (USB), Bluetooth®, Infrared Data Association(IRDA), and various radio frequency (RF) communication protocols definedby the IEEE 802.11 or other standards.

In the example of FIG. 1, input device 100 includes a sensor 105. Thesensor 105 comprises one or more sensing elements configured to senseinput provided by one or more input objects in a sensing region of theinput device 100. Examples of input objects include fingers, styli, andhands. The sensing region may encompass any space above, around, in,and/or proximate to the sensor 105 in which the input device 100 is ableto detect user input (e.g., user input provided by one or more inputobjects). The sizes, shapes, and/or locations of particular sensingregions (e.g., relative to the electronic system) may vary depending onactual implementations. In some embodiments, the sensing region mayextend from a surface of the input device 100 in one or more directionsinto space, for example, until a signal-to-noise ratio (SNR) of thesensors fall below a threshold suitable for accurate object detection.For example, the distance to which this sensing region extends in aparticular direction may be on the order of less than a millimeter,millimeters, centimeters, or more, and may vary significantly with thetype of sensing technology used and/or the accuracy desired. In someembodiments, the sensor 105 may detect input involving no physicalcontact with any surfaces of the input device 100, contact with an inputsurface (e.g., a touch surface and/or screen) of the input device 100,contact with an input surface of the input device 100 coupled with someamount of applied force or pressure, and/or a combination thereof. Invarious embodiments, input surfaces may be provided by surfaces ofsensor substrates within which or on which sensor elements arepositioned, or by face sheets or other cover layers positioned oversensor elements.

The input device 100 comprises one or more sensing elements fordetecting user input. Some implementations utilize arrays or otherregular or irregular patterns of sensing elements to detect the inputobject. The input device 100 may utilize different combinations ofsensor components and sensing technologies to detect user input in thesensing region.

The input device 100 may utilize various sensing technologies to detectuser input. Example sensing technologies may include capacitive,elastive, resistive, inductive, magnetic, acoustic, ultrasonic, andoptical sensing technologies. In some embodiments, the input device 100may utilize capacitive sensing technologies to detect user inputs. Forexample, the sensing region may include one or more capacitive sensingelements (e.g., sensor electrodes) to create an electric field. Theinput device 100 may detect inputs based on changes in capacitance ofthe sensor electrodes. For example, an object in contact with (or closeproximity to) the electric field may cause changes in the voltage and/orcurrent in the sensor electrodes. Such changes in voltage and/or currentmay be detected as “signals” indicative of user input.

The sensor elements may be arranged in arrays (regular or irregularpatterns) or other configurations to detect inputs. In someimplementations, separate sensing elements may be ohmically shortedtogether to form larger sensor electrodes. Some capacitive sensingimplementations may utilize resistive sheets that provide a uniformresistance.

Example capacitive sensing technologies may be based on“self-capacitance” (also referred to as “absolute capacitance”) and/or“mutual capacitance” (also referred to as “transcapacitance”).Transcapacitance sensing methods detect changes in the capacitivecoupling between sensor electrodes. For example, an input object nearthe sensor electrodes may alter the electric field between the sensorelectrodes, thus changing the measured capacitive coupling of the sensorelectrodes. In some embodiments, the input device 100 may implementtranscapacitance sensing by detecting the capacitive coupling betweenone or more transmitter sensor electrodes (also “transmitter electrodes”or “drive electrodes”) and one or more receiver sensor electrodes (also“receiver electrodes” or “pickup electrodes”). For example, transmittersensor electrodes may be modulated relative to a reference voltage totransmit transmitter signals while receiver sensor electrodes may beheld at a relatively constant voltage to receive the transmittedsignals. The reference voltage may be, for example, a substantiallyconstant voltage or system ground. In some embodiments, transmittersensor electrodes and receiver sensor electrodes may both be modulated.The signals received by the receiver sensor electrodes may be affectedby environmental interference (e.g., from other electromagnetic signalsand/or objects in contact with, or in close proximity to, the sensorelectrodes). Sensor electrodes may be dedicated transmitters orreceivers, or may be configured to both transmit and receive.

In some implementations, the input device 100 is configured to provideimages that span one, two, three, or higher dimensional spaces. Theinput device 100 may have a sensor resolution that varies fromembodiment to embodiment depending on factors such as the particularsensing technology involved and/or the scale of information of interest.In some embodiments, the sensor resolution is determined by the physicalarrangement of an array of sensing elements, where smaller sensingelements and/or a smaller pitch can be used to define a higher sensorresolution.

The input device 100 may be implemented as a fingerprint sensor having asensor resolution high enough to capture discriminative features of afingerprint. In some implementations, the fingerprint sensor has aresolution sufficient to capture minutia (including ridge endings andbifurcations), orientation fields (sometimes referred to as “ridgeflows”), and/or ridge skeletons. These are sometimes referred to aslevel 1 and level 2 features, and in an exemplary embodiment, aresolution of at least 250 pixels per inch (ppi) is capable of reliablycapturing these features. In some implementations, the fingerprintsensor has a resolution sufficient to capture higher level features,such as sweat pores or edge contours (i.e., shapes of the edges ofindividual ridges). These are sometimes referred to as level 3 features,and in an exemplary embodiment, a resolution of at least 750 pixels perinch (ppi) is capable of reliably capturing these higher level features.

In some embodiments, a fingerprint sensor is implemented as a placementsensor (also “area” sensor or “static” sensor) or a swipe sensor (also“slide” sensor or “sweep” sensor). In a placement sensor implementation,the sensor is configured to capture a fingerprint input as the user'sfinger is held stationary over the sensing region. Typically, theplacement sensor includes a two dimensional array of sensing elementscapable of capturing a desired area of the fingerprint in a singleframe. In a swipe sensor implementation, the sensor is configured tocapture a fingerprint input based on relative movement between theuser's finger and the sensing region. In some embodiments, the swipesensor may include a linear array or a thin two-dimensional array ofsensing elements configured to capture multiple frames as the user'sfinger is swiped or moves over the sensing region. The multiple framesmay then be reconstructed to form an image of the fingerprintcorresponding to the fingerprint input. In some implementations, thesensor is configured to capture both placement and swipe inputs.

In some embodiments, a fingerprint sensor is configured to capture lessthan a full area of a user's fingerprint in a single user input(referred to herein as a “partial” fingerprint sensor). Typically, theresulting partial area of the fingerprint captured by the partialfingerprint sensor is sufficient for the system to perform fingerprintmatching from a single user input of the fingerprint (e.g., a singlefinger placement or a single finger swipe). Some exemplary imaging areasfor partial placement sensors include an imaging area of 100 mm² orless. In another exemplary embodiment, a partial placement sensor has animaging area in the range of 20-50 mm². In some implementations, thepartial fingerprint sensor has an input surface that is of the same orsubstantially the same size as the imaging area.

In FIG. 1, a processing system 110 is included with the input device100. The processing system 110 may comprise parts of or all of one ormore integrated circuits (ICs) and/or other circuitry components. Theprocessing system 110 is coupled to the sensor 105, and is configured tooperate hardware of the input device 100 (e.g., sensing hardware of thesensor 105) to detect input in the sensing region.

The processing system 110 may include driver circuitry configured todrive sensing signals with sensing hardware of the input device 100and/or receiver circuitry configured to receive resulting signals withthe sensing hardware. For example, processing system 100 may beconfigured to drive transmitter signals onto transmitter sensorelectrodes of the sensor 105, and/or receive resulting signals detectedvia receiver sensor electrodes of the sensor 105.

The processing system 110 may include a non-transitory computer-readablemedium having processor-executable instructions (such as firmware code,software code, and/or the like) stored thereon. The processing system110 can be implemented as a physical part of the sensor 105, or can bephysically separate from the sensor 105. Also, constituent components ofthe processing system 110 may be located together, or may be locatedphysically separate from each other. For example, the input device 100may be a peripheral device coupled to a computing device, and theprocessing system 110 may comprise software configured to run on acentral processing unit of the computing device and one or more ICs(e.g., with associated firmware) separate from the central processingunit. As another example, the input device 100 may be physicallyintegrated in a mobile device, and the processing system 110 maycomprise circuits and firmware that are part of a main processor of themobile device. The processing system 110 may be dedicated toimplementing the input device 100, or may perform other functions, suchas operating display screens, driving haptic actuators, etc.

The processing system 110 may operate the sensing element(s) of thesensor 105 of the input device 100 to produce electrical signalsindicative of input (or lack of input) in a sensing region. Theprocessing system 110 may perform any appropriate amount of processingon the electrical signals to translate or generate the informationprovided to the electronic system. For example, the processing system110 may digitize analog electrical signals received via the sensorelectrodes and/or perform filtering or conditioning on the receivedsignals. In some embodiments, the processing system 110 may subtract orotherwise account for a baseline associated with the sensor electrodes.For example, the baseline may represent a state of the sensor electrodewhen no user input is detected. Accordingly, the information provided bythe processing system 110 to the electronic system may reflect adifference between the signals received from the sensor electrodes and abaseline associated with each sensor electrode. As yet further examples,the processing system 110 may determine positional information,recognize inputs as commands, recognize handwriting, match biometricsamples, and the like.

In some embodiments, the input device 100 may include a touch screeninterface (e.g., display screen), as well as a fingerprint sensor,wherein a sensing region of the fingerprint sensor at least partiallyoverlaps a sensing region of the touch screen interface. The displaydevice may be any suitable type of dynamic display capable of displayinga visual interface to a user, including an inorganic light-emittingdiode (LED) display, organic LED (OLED) display, cathode ray tube (CRT),liquid crystal display (LCD), plasma display, electroluminescence (EL)display, or other display technology. The display may be flexible orrigid, and may be flat, curved, or have other geometries. The displaymay include a glass or plastic substrate for thin-film transistor (TFT)circuitry, which may be used to address display pixels for providingvisual information and/or providing other functionality. The displaydevice may include a cover lens (sometimes referred to as a “coverglass”) disposed above display circuitry and above inner layers of thedisplay module, and the cover lens may also provide an input surface forthe input device 100. Examples of cover lens materials include opticallyclear amorphous solids, such as chemically hardened glass, and opticallyclear crystalline structures, such as sapphire. The input device 100 andthe display device may share physical elements. For example, some of thesame electrical components may be utilized for both displaying visualinformation and for input sensing with the input device 100, such asusing one or more display electrodes for both display updating and inputsensing. As another example, the display screen may be operated in partor in total by the processing system 110 in communication with the inputdevice 100.

FIG. 2 is a block diagram depicting the input device 100 as including afingerprint sensor 205. The fingerprint sensor 205 is configured tocapture an image of the fingerprint from a finger 240. The fingerprintsensor 205 is disposed underneath a cover layer 212 that provides aninput surface for the fingerprint to be placed on or swiped over thefingerprint sensor 205. The sensing region 220 may include an inputsurface with an area larger than, smaller than, or similar in size to afull fingerprint. The fingerprint sensor 205 has an array of sensingelements with a resolution configured to detect surface variations ofthe finger 240. In certain embodiments, the fingerprint sensor 205 maybe disposed within the active area of a display.

FIG. 3 depicts an exemplary orthogonal grid of transmitter electrodesand receiver electrodes of a fingerprint sensor device (e.g.,fingerprint sensor 205). It will be appreciated that this example, whichdepicts a 56×144 array (56 RX electrodes and 144 TX electrodes) ismerely illustrative, and that other configurations may be used as well,including, for example, 56×96, 80×80, 88×116, 72×80, etc. It willfurther be appreciated that although a grid with transmitter electrodesand receiver electrodes orthogonal to one another in a bars and stripesconfiguration is used herein as an example, other exemplaryimplementations of a fingerprint sensor device may utilize otherconfigurations of transmitter electrodes and receiverelectrodes—including, for example, single-layer configurations withinterdigitated electrodes, matrix configurations where each pixelcorresponds to an electrode plate, orthogonal diamond configurations,etc.

FIG. 4 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for a low-resolution scan (the activetransmitter electrodes are shown with a solid line, whereas the inactivetransmitter electrodes are shown with a dotted line). In this example,nine TX electrodes 401-409 of the 144 TX electrodes are driven todetermine whether or not a fingerprint is present proximate to each ofthe nine TX electrodes, and these nine TX electrodes 401-409 aredistributed over the input sensing region. It will be appreciated thatin other examples, a different number and/or a different distribution ofTX electrodes may be used.

To detect a fast finger motion, such as a fast swipe motion fromleft-to-right, a plurality of low-resolution scans to determine fingerpresence is performed. It will be appreciated that CDM may or may not beused for these low-resolution finger presence scans (but even if CDM isused, decoding is not needed for identifying finger presence). If CDM isnot used, each scan may include nine sub-steps, with each sub-stepcorresponding to a respective electrode out of the nine TX electrodes401-409 being driven. If CDM is used, each scan may still include ninesub-steps, with each sub-step corresponding to all nine TX electrodes401-409 being driven (e.g., using a 9×9 drive matrix for CDM9).

FIGS. 5A-5C illustrates a series of exemplary scans being performed as afinger moves from left to right. FIG. 5A shows an example of a firstscan being performed while a finger is located on the left side of theexemplary orthogonal grid of transmitter electrodes and receiverelectrodes from FIG. 3. During this first scan, the correspondingfingerprint sensor device is able to determine that the finger 501 ispresent over TX electrodes 401-404 and is not present over TX electrodes405-409. In this situation, the measured values at the RX electrodes forthe first through fourth sub-steps (corresponding to TX electrodes401-404 being driven, respectively) is different from the measuredvalues at the RX electrodes for the fifth through ninth sub-steps(corresponding to TX electrodes 405-409 being driven, respectively). Themeasured values at the RX electrodes for the first through fourthsub-steps indicate that a finger is present proximate to TX electrodes401-404, for example, based on comparing the measured capacitance valuesto a first threshold. The measured values at the RX electrodes for thefifth through ninth sub-steps indicate that a finger is not presentproximate to TX electrodes 405-409, for example, based on comparing themeasured capacitance values to a second threshold (which may or may notbe the same as the first threshold).

FIG. 5B shows an example of a second scan being performed while a fingeris located over the entirety of the exemplary orthogonal grid oftransmitter electrodes and receiver electrodes from FIG. 3. During thissecond scan, the corresponding fingerprint sensor device is able todetermine that the finger 501 is present over all of TX electrodes401-409.

FIG. 5C shows an example of a third scan being taken while a finger islocated on the right side of the exemplary orthogonal grid oftransmitter electrodes and receiver electrodes from FIG. 3. During thisthird scan, the corresponding fingerprint sensor device is able todetermine that the finger 501 is present over TX electrodes 406-409 andis not present over TX electrodes 401-405.

Because each low-resolution scan includes only a small subset of TXelectrodes being driven, and because the processing system is merelydetermining where the finger is present for each scan (rather thanobtaining a full image of the input sensing region for each scan), aplurality of low-resolution scans can be performed very quickly and withlow processing times. Thus, even if there is very fast finger motion(e.g., up to 50 centimeters per second or up to even greater speeds)where the finger passes through the three positions shown in FIGS. 5A-5Cvery quickly, the fingerprint sensor device is able to keep up andacquire a series of scans which indicate that a fast finger motion hasoccurred. For example, based on three scans corresponding to each ofFIGS. 5A-5C, a processing system of a fingerprint sensor device is ableto determine that a fast swipe gesture from left-to-right has occurred(e.g., based on determining that the finger was first present at theleft side of the sensing region, then present at the middle of thesensing region, then present at the right side of the sensing region,over a short time interval).

Further, it will be appreciated that scanning this small subset ofelectrodes (e.g., 9 electrodes out of 144 electrodes) can be performedextremely quickly, and the framerate may be faster than necessary evenfor detecting fast finger motions. Thus, the fingerprint sensor devicemay include a waiting period between low-resolution scans (e.g., at1/10^(th) duty cycle) to reduce power consumption while still allowingfor detection of fast finger motions.

FIGS. 5A-5C provide an example of a fast swipe motion in a horizontaldirection. In other exemplary embodiments, a fast swipe motion in avertical direction may also be detected. For example, in the case of avertical swipe in a downwards direction, the input sensing region maystart off as being completely covered by the finger, followed by thetop-most receiver lines becoming uncovered first, followed by additionalreceiver lines becoming uncovered as the swipe continues. When thetop-most receiver lines become uncovered, the capacitance detected bythose receiver lines increases. As more and more receiver lines becomeuncovered, a ripple response is detected where capacitance increasesfrom top to bottom for a downwards swipe. Thus, based on detecting thisripple response from top to bottom, a downwards vertical swipe can bedetermined. Similarly, based on detecting a ripple response from bottomto top, an upwards vertical swipe can be determined.

FIG. 6 is a flowchart depicting a process for using a fingerprint sensordevice to perform NAV operations corresponding to fast finger motions.The process starts at stage 601 with a finger on a sensing surface of afingerprint sensor device. For example, a finger may be received at aninput sensing region of the fingerprint sensor device, and thefingerprint sensor device may determine to initiate scanning, forexample, based on a wake-on-finger (WOF) process. At stage 602, multiplelow-resolution scans (for example, low-resolution scans using a subsetof TX electrodes as discussed above with respect to FIGS. 5A-5C) areperformed. At stage 603, a processing system of the fingerprint sensordevice determines whether a fast finger motion, such as a fast swipe,has occurred based on the multiple low-resolution scans. Stage 603, mayinclude, for example, analyzing changes in finger presence relative tothe input sensing region of the fingerprint sensor device acrossdifferent low-resolution scans within a certain period of time anddetermining whether there has been a fast swipe of the finger, forexample, from left to right or right to left or upwards or downwards. Atstage 604, further processing may be performed based on thedetermination that a fast finger motion corresponding to a NAV operationhas occurred. For example, if the fast finger motion was a fast swipefrom right to left, the fingerprint sensor device may cause a displayedwebsite, application, or document to advance to a next page.

Thus, it will be appreciated that by using a subset of TX electrodes forlow-resolution scans based on finger presence, a fingerprint sensordevice may be used for NAV operations corresponding to fast fingermotions. Further, low-resolution scans may be performed with relativelylow power consumption and low computational complexity, and at very highframe rates. Moreover, utilizing low-resolution scans based on fingerpresence may be more accurate than conventional full-resolution scanswith respect to certain NAV operations, particularly where the NAVoperation includes situations where the finger is only partiallycovering the sensing region (full-resolution scans sometimes do notperform well under partial-coverage conditions) or where the fingermotion is fast (full-resolution scans are susceptible to blurring if thespeed of the finger motion is above a certain threshold).

In certain exemplary embodiments, each TX electrode of the subset of TXelectrodes used for the low-resolution scans is adjacent to at least oneTX electrode that is not used for the low-resolution scan.

In certain exemplary embodiments, the TX electrodes of the subset of TXelectrodes used for low-resolution scans may be distributed throughoutthe sensing region. In one example, the TX electrodes used forlow-resolution scans may be evenly distributed (i.e., each pair ofconsecutive active TX electrodes has a same number of inactive TXelectrodes between them). In other examples, the TX electrodes used forthe low-resolution scans may not be evenly distributed (e.g., havingdifferent numbers of inactive TX electrodes between each pair ofconsecutive active TX electrodes), so long as there is at least oneactive TX electrode in each of a plurality of regions of interest. Forexample, if the input sensing region is divided into just two regions ofinterest, there should be at least one active TX electrode on one side,and at least one active TX electrode on the other side. In anotherexample, if the input sensing region is divided into three regions ofinterest, there should be at least one active TX electrode in a centerregion, at least one active TX electrode in a region on one side of thecenter region, and at least one active TX in a region on the other sideof the center region.

In further exemplary embodiments, small groups of multiple adjacent TXelectrodes (such as two adjacent TX electrodes) distributed throughoutthe sensing region may be used for the low-resolution scanning.

FIG. 7 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for a hybrid low-resolution/full-resolution scan(the active transmitter electrodes are shown with a solid line, whereasthe inactive transmitter electrodes are shown with a dotted line). Inthis example, a first subset—six of the TX electrodes 401, 403, 404,406, 407, 409 of the 144 TX electrodes—as well as a second subset—threefull-resolution sub-regions 701, 702, 703 of 14 adjacent TX electrodeseach—are driven. The six TX electrodes 401, 403, 404, 406, 407, 409 areused for low-resolution scanning to determine whether or not a finger ispresent proximate to each of those six TX electrodes, whereas the threefull-resolution sub-regions 701, 702, 703 are used to provide afull-resolution sub-image corresponding to each respective sub-region.In a further exemplary embodiment, the TX electrodes in the sub-regions701, 702, 703 may also contribute to the low-resolution scanning—forexample, by activating all of the TX electrodes in each particularsub-region simultaneously and treating each sub-region as if it were asingle electrode for the purposes of the low-resolution scanning. Itwill be appreciated that in other examples, a different number of TXelectrodes may be used for low-resolution scanning (to determine whetheror not a finger is present proximate to each TX electrode), a differentnumber of full-resolution sub-regions may be used, a different number ofadjacent TX electrodes per full-resolution sub-region may be used,and/or a different distribution of TX electrodes or full-resolutionsub-regions may be used. For example, two full-resolution sub-regionsmay be used, one full-resolution sub-region may be used, fourfull-resolution sub-regions may be used, etc.

The subset of TX electrodes depicted as being driven in FIG. 7 includesboth a first subset of TX electrodes being used at a low-resolution forfinger presence detection and a second subset of TX electrodes(comprising three regions of adjacent TX electrodes) being used forcapturing full-resolution sub-images of the sensing region. Thefingerprint sensor device is thus able to provide scanning withdifferent resolutions corresponding to different parts of the inputsensing region, such that both finger coverage information andfingerprint sub-images are obtained to enable NAV operationscorresponding to fast finger motions and slow finger motions (e.g., thefinger coverage information may be used for detecting fast swipe motionsand the partial fingerprint images may be used for detecting slow scrollmotions).

In the example shown in FIG. 7, each scan may include 48 sub-steps, with6 sub-steps corresponding to TX electrodes 401, 403, 404, 406, 407, 409(either being driven one at a time without CDM or being drivensimultaneously with CDM) to determine whether or not a finger is presentproximate to each TX electrode and with 14 sub-steps corresponding toeach full-resolution sub-region 701, 702, 703. Each full-resolutionsub-region may be scanned at full resolution using, for example, CDMorder 14 (CDM14) where each set of 14 adjacent TX electrodes are drivenat the same time to increase the SNR for the full-resolution sub-regionscanning. In another example corresponding to FIG. 7, each scan mayinclude 51 sub-steps, with 9 sub-steps corresponding to TX electrodesand sub-regions 401, 701, 403, 404, 702, 406, 407, 703, 409 (with eachsub-region 701, 702, 703 being driven as if it were a single TXelectrode) to determine whether or not a finger is present proximate toeach TX electrode/sub-region and with 14 sub-steps corresponding to eachfull-resolution sub-region 701, 702, 703. In yet another example,instead of each sub-region 701, 702, 703 being driven as if it were asingle TX electrode for the low-resolution scanning, a subset of one ormore TX electrodes from each sub-region 701, 702, 703 may be used forthe low-resolution scanning.

The scanning configuration shown in FIG. 7 is thus able to detect bothfast finger motions (such as fast swipe motions) and slow finger motions(such as slow scroll motions) based on a plurality of scans. The 6 TXelectrodes 401, 403, 404, 406, 407, 409 (plus, optionally, the threesub-regions 701, 702, 703 or a subset thereof being operated as 3additional low-resolution electrodes) may be used for low-resolutionscanning based on whether or not a finger is present, and thefingerprint sensor device is able to perform fast finger motion NAVoperations based on these 6 TX electrodes (plus the three sub-regions701, 702, 703 or a subset thereof) in a similar manner as discussedabove with respect to FIGS. 3-6. The full-resolution sub-regions 701,702, 703 are used to perform full-resolution imaging over thosesub-regions, and the fingerprint sensor device is able to perform slowfinger motion NAV operations based on analyzing the motion offingerprint features (e.g., movement of ridges and/or valleys) acrossmultiple scans.

It will be appreciated that since this hybrid scanning techniqueutilizes full-resolution sub-regions (corresponding to subsets of the TXelectrodes of the fingerprint sensor) to determine slow finger motionsrather than using full-image scanning (which utilizes all TX electrodesof the fingerprint sensor), slow finger motion NAV operations may beaccomplished by this hybrid scanning technique at lower power and lowercomputational complexity relative to conventional fingerprint sensorswhich rely on full-image scanning to perform slow finger motion NAVoperations.

It will be appreciated that the full-resolution sub-regions are notrequired to be “full resolution” in the sense that all TX electrodes ofthe sub-region are directly adjacent to one another. Instead, thesub-regions may be “high-resolution” sub-regions, which may or may notbe full-resolution sub-regions. For example, a high-resolutionsub-region may include 14 TX electrodes that are not immediatelyadjacent but are still relatively close together to provide a relativelyhigh resolution sub-image (e.g., each active TX electrode of thehigh-resolution sub-region may be separated from a next active TXelectrode of the high-resolution by having one or two inactive TXelectrodes between them).

FIG. 8 is a flowchart depicting a process for using a fingerprint sensordevice to perform NAV operations corresponding to slow and/or fastfinger motions. The process starts at stage 801 with a finger on asensing surface of a fingerprint sensor device. For example, a fingermay be received at an input sensing region of the fingerprint sensordevice, and the fingerprint sensor device may determine to initiatescanning, for example, based on a wake-on-finger (WOF) process. At stage802, multiple hybrid scans (for example, hybrid scans using a subset ofTX electrodes similar to the hybrid scans discussed above with respectto FIG. 7) are performed. At stage 803, a processing system of thefingerprint sensor device determines whether a finger motion, which maybe a fast finger motion such as a fast swiping motion or a slow fingermotion such as a slow scrolling motion, has occurred based on themultiple hybrid scans.

Stage 803, may include, for example, analyzing changes in fingerpresence relative to the input sensing region of the fingerprint sensordevice across different scans (based on spaced-out TX electrodes 401,403, 404, 406, 407, 409 which are used to determine finger presence)within a certain period of time and determining whether there has been afast-swipe movement of the finger, for example, from left to right orright to left or upwards or downwards. Stage 803 may also include, forexample, analyzing captured full-resolution (or high-resolution)sub-images corresponding to one or more of the sub-regions 701, 702, 703corresponding to 14 adjacent TX electrodes and determining whether therehas been a slow scroll movement of the finger, for example, upwards,downwards, to the left, or to the right.

Analyzing the captured sub-images of a particular sub-region may includecorrelating ridges present in one sub-image to ridges present in anothersub-image to determine whether or not there is movement of the ridges.Since the sub-image size (e.g., 56×14) is smaller than the full inputsensing region, the correlation processing is relatively fast. Usingeven smaller sub-images (such as using less than all RX electrodes—e.g.,14×14) may increase the processing speed even further.

Stage 803 may further include determination of finger speed based on themovement of fingerprint features between two or more scans (asdetermined by comparing captured sub-images), such that differentactions may be taken at stage 804 based on different NAV operationscorresponding to different determined speeds.

At stage 804, further processing may be performed based on thedetermination that a finger motion corresponding to a NAV operation hasoccurred. For example, if the fast finger motion was a fast swipe fromright to left, the fingerprint sensor device may cause a displayedwebsite, application, or document to advance to a next page or toquickly scroll to the right (and the speed of the scroll may be based onthe speed of the motion). In another example, if a slow finger motionwas a slow scroll upwards, the fingerprint sensor device may cause adisplayed website, application, or document to gradually scrolldownwards (and the speed of the scroll may be based on the speed of themotion). In other examples, if there is no motion detected, thefingerprint sensor device may determine that there has been a tap, adouble-tap, or a long press.

Thus, it will be appreciated that by using a subset of TX electrodes fora hybrid scan (including using certain TX electrodes for determinationof finger presence and other TX electrodes for capturing full-resolutionsub-images), a fingerprint sensor device may be used for NAV operationscorresponding to both fast finger motions and slow finger motions.Further, the hybrid scans may be performed with relatively low powerconsumption and low computational complexity and at relatively highframe rates (relative to fully scanning the input sensing region).Moreover, utilizing hybrid scans (which include using certain TXelectrodes for determination of finger presence) may be more accuratethan conventional full-resolution scans with respect to certain NAVoperations, particularly where the NAV operation includes situationswhere the finger is only partially covering the sensing region(full-resolution scans sometimes do not perform well underpartial-coverage conditions) or where the finger motion is fast(full-resolution scans are susceptible to blurring if the speed of thefinger motion is above a certain threshold).

FIG. 9 depicts the exemplary orthogonal grid of transmitter electrodesand receiver electrodes from FIG. 3 with a subset of transmitterelectrodes being driven for an abbreviated hybridlow-resolution/full-resolution scan (the active transmitter electrodesare shown with a solid line, whereas the inactive transmitter electrodesare shown with a dotted line). The abbreviated hybrid scan is similar tothe hybrid scan shown in FIG. 7, except that it provides lessfull-resolution sub-images because less full-resolution sub-regions of14 adjacent TX electrodes are used. In the example shown in FIG. 9, onlyone sub-region 901 of 14 adjacent TX electrodes is used.

In the example shown in FIG. 9, each scan may include 20 sub-steps, with6 sub-steps corresponding to TX electrodes 401, 403, 404, 406, 407, 409(either being driven one at a time without CDM or being drivensimultaneously with CDM) to determine whether or not a finger is presentproximate to each TX electrode and with 14 sub-steps corresponding tothe full-resolution sub-region 901. The full-resolution sub-region maybe scanned at full-resolution using, for example, CDM order 14 (CDM14)where the 14 adjacent TX electrodes are driven at the same time toincrease the SNR for the full-resolution sub-region scanning.

It will thus be appreciated that the abbreviated hybrid scancorresponding to FIG. 9 may be performed more quickly, with lesscomplexity, and with less power than the hybrid scan corresponding toFIG. 7. In certain examples, hybrid scanning was performed at aframerate of 500-1000 at an acceptable SNR level, while abbreviatedhybrid scanning was performed at a framerate of more than 3000 fps at anacceptable SNR level.

In certain exemplary embodiments, the one or more full-resolutionsub-regions used for successive abbreviated hybrid scans may changebased on finger coverage of the input sensing region changing (e.g., ina first abbreviated hybrid scan, only the full-resolution sub-region 701may be used, but based on the finger moving, only the full-resolutionsub-region 702 may be used in a later abbreviated hybrid scan).

FIG. 10 is a flowchart depicting a process for using a fingerprintsensor device to perform NAV operations corresponding to slow and/orfast finger motions. FIG. 10 is similar to FIG. 8, except that stage 802is replaced with stage 1002, i.e., instead of performing only hybridscans, the process shown in FIG. 10 includes performing both one or morehybrid scans and one or more abbreviated hybrid scans.

In one exemplary “double scan” embodiment, performing scanning at stage1002 includes performing multiple double scans, wherein each double scanincludes performing a hybrid scan followed by an abbreviated hybridscan, wherein one or more full-resolution sub-regions for theabbreviated hybrid scan is selected based on the finger coveragedetermined from the respective preceding hybrid scan. For example, ofthe three sub-regions 701, 702, 703 shown in FIG. 7, sub-region 701 maybe selected for the abbreviated hybrid scan (e.g., as shown in FIG. 9)if the finger is determined as being present in sub-region 701 and notpresent in sub-regions 702 and 703. The fingerprint sensor device mayutilize an adjustable waiting period between double scans to achieve adesired framerate and/or a desired amount of power consumption.

In another exemplary embodiment, performing scanning at stage 1002includes performing a hybrid scan followed by multiple abbreviatedhybrid scans, wherein the one or more full-resolution sub-regions forthe multiple abbreviated hybrid scans is selected based on the hybridscan. The fingerprint sensor device may also utilize an adjustablewaiting period between scans in this embodiment to achieve a desiredframerate and/or a desired amount of power consumption. In one example,a single hybrid scan is performed followed by only abbreviated hybridscans being performed thereafter until a stop condition is met (e.g., anamount of time elapsing, the finger moving to a differentfull-resolution sub-region, detecting that the finger has left thesensor, etc.). In another example, the hybrid scans are performedperiodically with multiple abbreviated hybrid scans being performedbetween two hybrid scans.

FIG. 11 is a flowchart depicting a process for using a fingerprintsensor device to perform NAV operations corresponding to slow and/orfast finger motions. FIG. 11 is similar to FIG. 10, except that stage1002 is replaced with stage 1102—i.e., instead of performing hybridscans and abbreviated hybrid scans, the process shown in FIG. 11includes performing both one or more low-resolution scans and one ormore abbreviated hybrid scans.

In one exemplary “double scan” embodiment, performing scanning at stage1102 includes performing multiple double scans, where each double scanincludes performing a low-resolution scan followed by an abbreviatedhybrid scan, wherein one or more full-resolution sub-regions for theabbreviated hybrid scan is selected based on the finger coveragedetermined from the respective preceding hybrid scan. For example, basedon a low-resolution coverage scan as shown in FIG. 3, sub-region 901 maybe selected for the abbreviated hybrid scan (e.g., as shown in FIG. 9)if the finger is determined as being present in that sub-region and notin other sub-regions. The fingerprint sensor device may utilize anadjustable waiting period between double scans to achieve a desiredframerate and/or a desired amount of power consumption.

In another exemplary embodiment, performing scanning at stage 1102includes performing a low-resolution scan followed by multipleabbreviated hybrid scans, wherein the one or more full-resolutionsub-regions for the multiple abbreviated hybrid scans is selected basedon the low-resolution scan. The fingerprint sensor device may alsoutilize an adjustable waiting period between scans in this embodiment toachieve a desired framerate and/or a desired amount of powerconsumption. In one example, a single low-resolution scan is performedfollowed by only abbreviated hybrid scans being performed thereafteruntil a stop condition is met (e.g., an amount of time elapsing, thefinger moving to a different full-resolution sub-region, detecting thatthe finger has left the sensor, etc.). In another example, thelow-resolution scans are performed periodically with multipleabbreviated hybrid scans being performed between two low-resolutionscans.

In yet another exemplary embodiment, performing scanning may includeperforming multiple low-resolution scans and determining whether or nota fast finger motion is in progress, and if it is determined that a fastfinger motion is in progress, no hybrid scans and no abbreviated hybridscans are performed. Rather, the fingerprint sensor continues to justperform low-resolution scans (since the higher level of detail providedby hybrid scans and abbreviated hybrid scans would not be needed toevaluate the fast finger motion that is in progress).

It will be appreciated that although the illustrative examples discussedabove are provided in the context of transcapacitive fingerprint sensordevices, the principles described herein may also be applied to othertypes of input devices, such as fingerprint sensors using absolutecapacitance sensing techniques, as well as optical fingerprint sensors.For example, in an absolute capacitance fingerprint sensor, less thanall of the electrodes may be used to carry out fast scanning and/orhybrid scanning as described herein. Similarly, in an opticalfingerprint sensor, less than all of the pixels may be used to carry outfast scanning and/or hybrid scanning as described herein.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and “at least one” andsimilar referents in the context of describing the invention (especiallyin the context of the following claims) are to be construed to coverboth the singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The use of the term “at least one”followed by a list of one or more items (for example, “at least one of Aand B”) is to be construed to mean one item selected from the listeditems (A or B) or any combination of two or more of the listed items (Aand B), unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Exemplary embodiments are described herein. Variations of thoseexemplary embodiments may become apparent to those of ordinary skill inthe art upon reading the foregoing description. The inventors expectskilled artisans to employ such variations as appropriate, and theinventors intend for the invention to be practiced otherwise than asspecifically described herein. Accordingly, this invention includes allmodifications and equivalents of the subject matter recited in theclaims appended hereto as permitted by applicable law. Moreover, anycombination of the above-described elements in all possible variationsthereof is encompassed by the invention unless otherwise indicatedherein or otherwise clearly contradicted by context.

1. A method for performing navigation (NAV) operations using a sensordevice comprising a plurality of transmitter electrodes, the methodcomprising: receiving, at an input sensing region of the sensor device,an input object; scanning, by the sensor device, the input object,wherein the scanning comprises driving a first subset of transmitterelectrodes for low-resolution scanning and a second subset oftransmitter electrodes for high-resolution scanning; and determining, bythe sensor device, an input object motion based at least in part on thescanning.
 2. The method according to claim 1, further comprising:determining input object coverage based at least in part on thelow-resolution scanning; and capturing a sub-image of the input objectbased at least in part on the high-resolution scanning.
 3. The methodaccording to claim 1, wherein the second subset of transmitterelectrodes for high-resolution scanning includes one or more groups ofadjacent transmitter electrodes.
 4. The method according to claim 1,wherein the first subset of transmitter electrodes for low-resolutionscanning includes transmitter electrodes distributed throughout theinput sensing region.
 5. The method according to claim 1, wherein one ormore electrodes of the second subset of transmitter electrodes forhigh-resolution scanning are also part of the first subset oftransmitter electrodes for low-resolution scanning.
 6. The methodaccording to claim 1, wherein determining the input object motioncomprises determining a fast swipe NAV motion based on thelow-resolution scanning.
 7. The method according to claim 1, whereindetermining the input object motion comprises determining a slow scrollNAV motion based on the high-resolution scanning.
 8. The methodaccording to claim 1, wherein the input object is a finger.
 9. Themethod according to claim 1, wherein the input object is a stylus. 10.The method according to claim 1, wherein the input object is a hand. 11.A non-transitory computer-readable medium having processor-executableinstructions stored thereon for performing navigation (NAV) operationsusing a sensor device, the processor-executable instructions, whenexecuted, facilitating performance of the following: scanning, by thesensor device, an input object at an input sensing region of the sensordevice, wherein the scanning comprises driving a first subset oftransmitter electrodes for low-resolution scanning and a second subsetof transmitter electrodes for high-resolution scanning; and determining,by the sensor device, an input object motion based at least in part onthe scanning.
 12. The non-transitory computer-readable medium accordingto claim 11, wherein the scanning includes: determining input objectcoverage based at least in part on the low-resolution scanning; andcapturing a sub-image of the input object based at least in part on thehigh-resolution scanning.
 13. The non-transitory computer-readablemedium according to claim 11, wherein the second subset of transmitterelectrodes for high-resolution scanning includes one or more groups ofadjacent transmitter electrodes.
 14. The non-transitorycomputer-readable medium according to claim 11, wherein the first subsetof transmitter electrodes for low-resolution scanning includestransmitter electrodes distributed throughout the input sensing region.15. The non-transitory computer-readable medium according to claim 11,wherein determining the input object motion comprises determining a fastswipe NAV motion based on the low-resolution scanning.
 16. Thenon-transitory computer-readable medium according to claim 11, whereindetermining the input object motion comprises determining a slow scrollNAV motion based on the high-resolution scanning.
 17. The non-transitorycomputer-readable medium according to claim 11, wherein the input objectis a finger.
 18. The non-transitory computer-readable medium accordingto claim 11, wherein the input object is a stylus.
 19. Thenon-transitory computer-readable medium according to claim 11, whereinthe input object is a hand.
 20. A method for performing navigation (NAV)operations using a sensor device, the method comprising: receiving, atan input sensing region of the sensor device, an input object; scanning,by the sensor device, the input object, wherein the scanning comprisesdriving a first subset of transmitter electrodes of the sensor device todetermine coverage of the input sensing region by the input objectthrough multiple low-resolution scans; and detecting, by the sensordevice, based on the scanning, motion of the input object correspondingto a fast swipe NAV operation.